Figure REF  shows the largest exponent \(\theta \)  for which the quadruple \((R, \theta , \Delta _0, \Delta _1)\)  is achievable according to Theorem REF , and compares it to the exponent proposed in [1]} and the largest exponent achievable without any security constraints [2]}. For small rates \(R\) , all three exponents coincide and the equivocation constraints under both hypotheses seem inactive. For larger rates \(R\) , the optimal exponent in Theorem REF  dominates the sub-optimal exponent in [1]} because \(\epsilon >0\) . For even larger rates \(R\) , the security constraints become stringent the exponent in Theorem REF  is below the Ahlswede-Csiszàr exponent in [2]}.

